Method of and apparatus for recovering oil



* o Jwm 28 R927 L. RANNEY METHOD OF AND APPARATUS FOR nncovsnme 011.

Filed March 10, 1925 3 Sheets-Sheet 2 x wwwmmwwsww rm 1,6342 Juana 2 19270 L" RANNEY 36 METHOD OF AND APPARATUS FOR RECOVEBING OIL.

Filed March 10. 1925 3 Shets-Sheet 5 1'4 I Z0 0 3 I 6 i J W 6cm wags Patented June 28, 1927 UNITED STATES PATENT OFFICE.

LEO RANNEY, OF JACKSBOBO, TEXAS, ASSIGNOR TO STANDARD nnvnnorm'r PANY, A CORPORATION OF DELAWARE.

i METHOD OF AND APPAIRATUS FOB RECOYERING OIL.

Application filed March 10, 1925. Serial No. 14,448.

This invention relates to a method and system for recovering oil from the earth by a mining operation and is an improvement upon the subject matter of my prior applications Serial No. 683,703, filed December 31, 1923, formethod of recovering 011, and Serial-No. 711,596, filed May 7, 1924, for apparatus for recovering 011.

The invention will be understood from the following description, taken in connectlon with the accompanying drawmgs:

In the drawings, Fig. 1 is a sectional elevation of a system embodying the invention; Fig. 2 is a similar detail view of another arrangement; Fig. 3 is a detail view of a conduit; Fig. 4 is a view corresponding to Fi 1 and showing an arrangement for ut1- lizing heat; Fig. 5 is a cross section on the line 55, Fig. 4; Fig. 6 is a sectional plan view, illustrating another feature of the invention and having particular reference to the arrangement of oil-collecting conduits; Fig. 7r'is a vertical section through a dralnage tube; and Fig. 8 is a sectional elevation, somewhat diagrammatic, illustrating another arrangement of conduits.

According to my system of mining for oil, as developed in the prior pending applications referred to, the oil sand is reached by simple mining methods, including the sinking of a shaft 1 and the tunneling or opening of galleries or rooms 2 in various directions along the oil' sand in a region contiguous thereto or at approximately the level thereof. Such galleries may be at a depth of several thousand feet and only a relatively short distancea few feet above or below the oil-bearing sand 3. They are so dug and arranged as to expose or render accessible to the workmen as great an area as possible of the underlying or overlying oil-bearing sand and therefore.

provide entrance to the-field by short and relatively inexpensive holes at any desired number of more or less closely spaced points. The cost of each such hole in comparison to the cost of drilling from the surface is obviously insignificant. Having tapped the field at any desired number of such holes the oil drained from the sand is led by a series of nipples 4 into a collecting system including the main pipes 5 leading to a sump or collecting vessel 6 from which the product of all of the nipples or wells may be elevated to the surface by the pump 7 discharging through a pipe 8 into a field pipe line or the surface reservoir 9.

Experience has shown that this system is most eificiently operated when proper provisions are made both for inevitably causing the oil in the sand to enter the conducting system and preventing undesirable materials or conditions, such as gas, water, or the pressure of air artificially introduced to the field, from substantially. influencing such conducting system. According to my invention this is accomplished by sealing or closing off the collecting system, and especially the conduits, nipples or pipes which enter the oil sand, from what may be termed -offending strata. An offending stratum may be a layer of material in streaks separated by parting or cleavage planes affording avenues of escape along said planes, a layer of coarse or porous material above, below, or in the oil-bearing sand, or a layer of material containing any channel or avenue through which water, air, gas or the like may enter the conducting system or through which the oil to be recovered may escape. Care is taken to seal off all such offending strata.

Nevertheless, the system adapts itself for simultaneously tapping or draining, through each one of any number of holes or conduits, two or more distinct oiLbearin strata separated by a porous or leaky o endin stratum. For example, in Fig. 1 the gafi lies just above the cap rock 10, below which is the oil-bearing sand. This oil-bearing sand, however, may be assumed to include two good oil-producing strata 3, 3", the upper stratum 3 being bounded below by an impervious layer of parting rock 11 below which is the leaky or porous offending stratum l2, and possibly a thin streak 11 of shale, lying above the oil-bearing stratum 3". As shown, the bed rock 11 and ofi'ending stratum 12 pinch ofi" to the right the upper oil-bearing stratum 3 Obviously, the offending stratum 12 will afford an avenue of escape for oil, gas or air permitted to enter it, or might permit water to reach the collecting system. The collecting pipe or nipple 4, therefore, extends oil-bearing sand 3", the bed rock 11, the shale 11, the olfending stratum 12 and into the oil-bearing sand 3* to a level where it is desired to collect the oil. The hole may extend beyond the end of the conduit or pipe to any desired distance, as indicated at 13.

The pipe or conduit is sealed from the cap rock 10 to prevent escape of oil or gas into the tunnel, and is also sealed from the bed rock 11 and porous streak 12, by a packing or packings 14, which maybe of any suitable form to seal the joint and close off any communication between the conducting system and the ofi'endingt stratum. The sealing plug or packing may be of tar or bituminous material, lead wool, asphalt, or other materials, and may be introduced into position in any desired manner. In the instance described it is desirable to tap or drain the upper layer 3 of oil-producm sand. The pipe, therefore, may be provi ed with perforations 15 afi'ording communication from the stratum 3 to the conducting system and in this case the lower packing or strata 11, 12 is first inserted and is terminated at the level of the bed rock 11. before the upper packing is inserted.

It should also be noted that in many cases the perforations 15, Fig. 1, will be unnecessary and may be omitted and the conduit will be open to the oil sand only at its end. ln all such cases, whether the tunnel is above or below the oil sand the oil will drain to the conduit by gravity or the expulsive effect of hydrostatic pressure, or the pressure of gas,

air or the like. There is no liability of the wall of a shot hole, such as are used in surface well systems. being closed or choked by-paratlin congealed either by external air circulated over it or by draining the hole dry and uncovering its wall.

Sometimes it happens that the pressure of air or other gas introduced into a field to assist in driving out the oil and thereby stimulate production finds a ready avenue of quick escape along the wall of the nipple and into the conducting system. In such cases it is beneficial to continue the sealing plug clear to the end of the pipe, as shown at 16.

One of the essential features of a proper collecting pipe or conduit for this system is a wall that is impervious where it passes through any ofiending stratum. The pipe or conduit must be so arranged in the strata that its wall or the packing around its wall prevents communication along the outside of the conduit betweensuccessive strata. In this way communication between offending strata and both the useful strata and the conducting system is avoided. In some cases, as where the cap rock is an impervious non-porous material, such as igneous rock, a mere hole through the rock is a sealed impervious conduit.

While in Fig. 1 I have shown the collect: ing nipple or conduit as a ipe extending from themain 5 clear to t 0 oil bearing sand, nevertheless this pipe or conduit may be of other forms. The conduit itself may be formed by or in the sealing plug. For

example, and as shown in Fig. 3, a full size hole may be bored or drilled from the tunnel to the desired level. in the oil-bearing,

munication is afforded from the oil-bearin sand to the collecting system and the we of the plug becomes a conduit sealed from the stratum.

Fig. 1 shows penetration of the oil-bearing sand from galleries or rooms located above the sand, but in all of the various examples herein described, the sand may be tapped from tunnels, rooms, or galleries below it. This is illustrated in Fig. 2 and is described also in my prior pending applications referred to. Indeed, the same mine may include some rooms or galleries above the oil sand and other rooms or galleries below it. Again, it is not necessary that the floor of the gallery shall actually be a caprockabove the oil sand, nor, when working from below need the roof of the tunnel be the bed rock below the oil sand. The im portant thing is the location of the tunnels, rooms, and galleries at a level so near the oil-bearing sand as to reduce the cost of drilling each hole separately from the sur face. Considerations of economy in the cost of tunneling, especially a differential between the costs of drilling in soft and hard rock, may dictate forming the tunnel at a level an appreciable distance from the cap rock or bed rock, say even up to 25 or 50 feet. If a soft stratum easily tunneled is near the oil-bearing sand it may be cheaper to tunnel in such stratum and pierce the individual strata at each well. A cap rock or bed rock five feet or so thick and streaked or striated with porous material or cross fissured may be the best of reasons for placing the floor or roof of the tunnel, as the case may be, a material distance above suchcap rock or below such bed rock.

Again, the cap rock is frequently of undulating or wavy character and nevertheless the'tunnel roof or floor should be level, or

on a fairly even inclination where there is a off from the conducting system and from producing stratav by interposing the plugs or packin s 14 between the conduit and the inner sur ace of the hole through such offending strata, as before described.

In Figs. 4 and 5 an important phase of the present invention is illustrated; that is, the formation of drainage areas of wide extent within the oil-bearing .sand. It is has heretofore been proposed to excavate mine galleries or tunnels through the oil-bean ing sand. Oil drains into the galleries and is collected. Owing to the presence of inflammable vapors and gases, this method of oil mining is extremely hazardous. Ao-v cording to my invention, the galleries are sealed from the oil and gas-producing strata, as previously described. Although avoiding the dangers of earlier tunneling operations for recovering oil, I have found that it is possible with my system to obtain the drainage effect of a tunnel excavated through the sand, and in many cases a drainage effect of much greater magnitude than has heretofore been attained, without the actual removal of any sand. I provide ,what may be termed an unexcavated drainage tunnel or area of facilitated-flow of oil.

In a preferred method of obtaining this result I apply heat to form a zone from which oil is removed, leaving the zone free to receive oil from adjacentoutlying regions of the sand. As the heating is continued, the zone becomes progressively larger. Ordinarily, a number of relatively closely spaced heating elements are provided so that the various zones of heat overlap to form a continuous passage or hot sand tunnel.

Referring to Figs. 4 and 5, some or each of the pipes, conduits, or wells from the tunnel into the oil sand are also used for subjecting the oil sand to a heating eflect, such as by heat-radiating return bends 20 connected to a steam supply pipe or other source of heat 21 and to discharge pipe 22. If desired, steam may also be introduced directly into the sand through the branch supply line 23'. However heated, whether by conduction or by contact of the steam with the sand, the heat effect at each hole in time extends outwardly until by proper spacing of the holes the heat zones of neighboring holes overlap, as indicated by theshaded zone A, Figs. 4 and 5. This zone of the oil-bearing sand is all heated and therefore soon gives up its oil, leaving its pores open and available as a. collector or reservoir for the remaining oil in neighboring cooler or unheated sand. The effect gradually works its way outward, so that an ever increasing area of oil-bearing sand is opened to attack.

Two or more of the hot sand tunnels may readily be operated conjointly, preferably with the combined effects of both suction and pressure therein, not only to stimulate and increase oil production, but also for extending the effective area of the hot sand said hot sand tunnels having its branch collecting pipe or main 5 from which the oil collecting nipples 4 extend into the oil bearing sand. Heat is applied at the several nipples by the steam plpes 20 from the steam supply pipe 21, so that both hot sand tunnels are constantly heated. In the shaft, or a gallery or room connected therewith, is located an air or gas pump 30, such as a steam-operated pump with valve-controlled connections 31 to the oil collecting mains 5 in the two galleries, said mains being also provided with valves 32 enabling each main to be shut off from the general collecting system. The valve arrangement will. be such as to enable the suction side of the pump 30 to be connected to either one of the branch pipes 5 and its discharge end to the other of said branch pipes 5. As a consequence, the heated gas in one hot sand tun nel may be withdrawn therefrom and discharged into the other hot sand tunnel, subjectmg the one to suction and the other to pressure. In that tunnel where suction is effective, oil flow will be stimulated or increased, whereas in the other tunnel where pressure is effective, the hot gas will flow outwardly and convey the heat through said tunnel to a greater distance from the wells than would be possible by heat-conduction through the sand itself. By -alternating the connections of the air pump to the two tunnels in the manner described the flow of oil is increased, and the hot sand tunnels are extended.

lVhile heating is ordinarily the most efficient method for forming unexcavated drainage tunnels or areas of facilitated fiow, various other procedures may be adopted. As illustrative, I shall describe a drainage. system involving the pumping of oil from the sand to provide an evacuated area into which further oil may flow. To accomplish this, holes are drilled at relatively small distances apart, so that the drained area of sand around each hole connects with the drained area around the adjacent holes. Further means are provided to keep the exposed surface of the sand substantially free from oil.

In Fig. 7 one means for doing this is shown. Reference numerals 33 and 34 denote the cap rock and the bed rock (lower cap rock) respectively. The oil sandis designated 35. The cap rock and the oil sand are drilled to provide holes or wells 36 of a small diameter. Only one of these is shown, but it will be understood that a large number are provided so that the drainage zones about them will overlap. A tube 37 is arranged in each hole 36 and each tubeadjacent its upper end is sealed exteriorly by a packing 38. The interior of the tube from the bottom of the hole and the face of the sand is substantially free of liquid from the top of the hole to the bottom. The

space between the tube and the wall of the hole is ordinarily occup1ed by gas under some pressure. which serves to prevent oil from collecting about the outside of the tube. Gravity, therefore, has full opportunity to act and creates a space evacuated of oil around each tube. In a short time these evacuated spaces meet and a drainage tunnel is formed. Suction or pressure, of course, will expedite the flow.

If the tunnel in which the collecting system. is located is below the level of the oilbearing sand, gravity alone may be depended upon to withdraw the oil from the holes. The formation of an unexcavated drainage tunnel in this case is otherwise similar to that just described. In both these cases and in similar situations, I provide one or more excavated tunnels sealed from oil and gasproducing strata, so that the operators may safely work in them, and lying more or less in a plane parallel to that of'the unexcavated drainage tunnel or tunnels. The cooperative use of these two kinds of tunnels is unique so far as I am aware, and has very important advantages.

The present system is also advantageous in its possibility of enabling the field operationsto be readily controlled and regulated in the most efficient manner. For example, in this system the line or zone of attack upon a given area of the field may be made to gradually decrease, whereas in ordinary surface well practice the effect upon the field at the bottom of eachwell extends out-- wardly in a gradually widening circle and with less eflicient effect as the distance from the well increases. As shown in Fig. 8, it is possible with the present system to arrange: the galleries 2 in grid-like form, somewhat tributing mains 5 along said galleries the oil-collecting nipples or conduits 4 leading from said mains 5 into the oil sand may be so. spaced at intervals alon the galleries as to surround the area B. 6f course, the oil-collecting effect at each of the several nipples extends outwardly from said nipple, but where a series of nipples surrounds a given tract the ever-increasing extent of the field of attack of the several nipples gradually moves the line of attack upon the oil field toward the center of the area B, as indicated by the dotted lines C. Efficiency of the system in withdrawing oil therefore tends to increase rather than diminish, as opposed to surface well practice.

It is also possible with my system to so control the field as to minimize coning effects, either of gas above the oil or of water beneath it. Referring for illustration to the coning effect of water, it is a well-known fact that water moves more easily through an oil sand than does oil. .When wells of relatively large diameter (6 inches or more) are drilled, the sand directly below the bottom of the well is rapidly drained of oil and may become filled with water, instead of with oil from adjacent sand. When such a water channel has become established, more and more water generally comes into the hole, gradually forming a cone-shaped area saturated with water. Eventually, this area may reach the top of the sand and prevent the further production of oil from the well.

I have found that the coning effect becomes less and less apparent as .the diameter of the well or hole is decreased. While it is impractical to drill surface wells of very small diameter, the collecting conduits provided in my system of operation may readily be made as small as desired. Owing to the distribution of a, multiplicity of small conduits throughout the field, it is possible to control the advance or recession of water, gas or other fiuids by proper arrangement of valves.

the well to allow the cbne to reoede.

When steam is used for heating or for motor purposes all exposed steam pipes will be jacketed with asbestos or the like to save heat and reduce condensation.

The operation of my mining system may be varied rather Widely to meet particular conditions. For example, when the system shown in Fig. 8 is employed, reversals of the air or gas pump will occur at intervals depending upon the desirability of rapidor Any portion of the collecting system, or the system as a whole, may be slower production and may be as frequent as one or two hours when a rapid supply of oil is desired and at less frequent intervals when rapidity of collection is not 1mportant. Reversals will also be more infrequent as the hot sand tunnels increase in size.

Various changes and alternative arrangements may be made within the scope of the a pended claims, in which I intend to claim all novelty inherent in the invention as broadly as the prior art permits.

I claim:

1. Apparatus for recovering oil from an oil-bearing stratum to which access is gained by a mine gallery, including an oil-collect ing conduit extending from the gallery to the oil-bearing stratum and sealing material interposed between the conduit and the stratum it traverses to prevent communication between the stratum and the gallery, except through the conduit.

2. Apparatus for recovering oil from an oil-bearing stratum to which access is gained by a mine gallery, and including a number of oil collecting nipples extending from the gallery toward said stratum, impervious material between each nipple and at least a portion of the region it traverses, said material sealing the exterior of the nipple with respect to the gallery, an opening extending into the oil-bearing stratum from the terminus of each nipple, whereby an extended area of drainage into each nipple is formed, and a pipe system having a valve-controlled connection with each nipple.

3. Apparatus for recovering oil from an oil sand to which access is gained by a mine gallery spaced from the sand by an im ervious stratum, and comprising a series 0 oil collecting nipples passing through said stratum, impervious sealing material between said nipples and stratum, said material sealing the exterior of the nipples with respect to the gallery, an opening extending into the oil sand from the terminus of -each nipple, whereby an extended area of drainage into the nipples is formed, and a collecting system into which the nipples discharge.

4. Apparatus for recovering oil from an oil-bearing stratum to which access is gained by a mine gallery, including a series of relatively closely spaced oil-collecting conduits extending from the gallery to the oil-bearing stratum, and means for applying heat to the oil-bearing stratum at closely spaced intervals, whereby the flow of oil 18 increased.

5. Apparatus for recovering oil from an oil-bearing stratum to which access is gained by a mine gallery, including a series of relatively closely spaced oil-collecting conduits extending from the gallery to the oil-bearing stratum, andv means for applying heat through said conduits to the oil-bearing stratum at such closely spaced intervals that the heated zones at the several points of application overlap and form a continuous heated area in the oil-bearing stratum, whereby the fiow of oil is increased.

6. Apparatus for recovering oil from an oil-bearing stratum to which access is gained by a mine gallery, including a series of relatively closely spaced oil-collecting conduits extending from the gallery to the oil-bearing stratum, means for applying heat to the oil-bearing stratum at such closely spaced intervals that the heated zones at the several points of application overlap and form a continuous heated area in the oil-bearing stratum, and means for sealing the conduit wallto close communication to the gallery except through said conduit and also to close communication between oil-bearing and offending strata.

7. Apparatus for recovering oil from an oil-bearing stratum to which access is gained by a mine gallery, including a series of relatively closely spaced oil-collecting conduits extending from the gallery to the oil-bearing stratum, means for applying heat through said conduits to the oil-bearing stratum at such closely spaced intervals that the heated zones at the several points of application overlap and form a continuous heated area in the oi1-bearing stratum, the evacuation of oil from such area producing an oil-collecting reservoir, and means for sealing the conduit wall to close communication to the gallery except through said conduit and also to close communication between oil-bearing and ofl'ending strata.

8. The method of increasing production of oil from an oil-bearing stratum to which ac cess is gained by a mine gallery, comprising collecting the oil through conduits cxtend-' ing from the gallery to the oil-bearing stratum and applying heat to the stratum at a plurality of closely spaced points, whereby the flow of oil is increased.

9. The method of recovering oil from an oil-bearing stratum to which access is gained by a mine gallery, comprising introducing at a plurality of closely spaced points in the stratum an amount of a flow-facilitating agent sufiicient to form a substantially con tinuous zone of facilitated flow, and withdrawing the oil from said zone, whereby the zone is left free to receive oil from other areas of the oil-bearing stratum.

10. The method of increasing production of oil from an oil-bearing stratum to which access is gained by a mine gallery, comprising forming a plurality of relatively closely spaced oil conduits from the gallery to the oil-bearing stratum, applying to the stratum at a plurality of relatively closely spaced points an amount of heat sufficient to form a substantially continuous heated zone and withdrawing the oil from said'heated zone, whereby the zone is left free to receive 011 from other areas of the oil-bearing stratum.

11. The method of operatin an oil field, comprising excavating a tunne adjacent the oil-bearing sand but separatedtherefrom by a substantially impervious area, tapping the sand from the tunnel by a number of relatively closed spaced openings havin plpes sealed therein, but not extending to t e ends of the openings, and withdrawing oil through said pipes, whereby an .unexcavated drainage tunnel generally paralleling the excavated tunnel is formed in the sand. it

12. The method of operating an oil field, comprising excavating a system of intersecting tunnels adjacent the 011-bearing sand but separated therefrom by a substantially impervious material, tapping the sand from the tunnels by a large number of relatively closely spaced openings having pipes sealed therein, but not extending to the ends of the openings, and withdrawing oil through said pipes, whereby a system of unexcavated drainage tunnels generally paralleling the excavated tunnels and separated therefrom by said substantially impervious material is formed in the sand.

13. The method of facilitating withdrawal of oil from an oil-bearing stratum to which access is gained by a mine gallery, comprising establishing in the stratum a relatively extensive zone of heat generally paralleling the gallery, discontinuing the heating, with drawing the oil from said zone whereby it is left free to receive oil from other areas of the oil-bearing stratum, again heating the zone to enlarge its extent, and successively repeating the withdrawal and heating.

14. The method of facilitating withdrawal of oil from an oil-bearing stratum to which access is gained by a mine gallery, comprising heating a relatively extensive zone of the stratum by means of hot gaseous fluid introations.

15. The method of facilitating withdrawal of oil from an oil-bearing stratum to which access is gained by a mine gallery, comprising heating a relatively extensive zone of the stratum by means of hot gaseous fluid, ap-"" plying such suction to said zone as to remove the hot gaseous fluid therefrom and forcing the same into another zone oflthe stratum, and successively repeating this cycle I of operations, whereby the zones are alter-' nately subjected to suction and to ressure.

16. In the recovery of oil from t e earth, the combination with a tunnel located adjacent but outside an oil bearing stratum, of a pipe system in said tunnel and communicating at a plurality of points'with then-oil bearing stratum, means for applying heat to at least some of such points, and means for preventing access of fluid from the oil bearing stratum to the tunnel except through the pipe system.

17 In the recovery of oil from the earth, the combination with a shaft and tunnels, said tunnelsbeing located at approximately the level of the oil bearing sand, but spaced therefrom by an impervious stratum, of a 75 pipe line system extending through said tunnels and having branch collectors extending from the tunnels into the oil bearin sand, and heating means for each of said branch collectors, such heating means comprising members' to which steam is supplied, members being closed against the oil e In testimony whereof I hereby aflix my signature.

LEO RANNEY. 

